Sulfomaleation of organic molecules and polymers

ABSTRACT

A covalently bonded reaction product of: 
     (a) a sulfomaleic anhydride adduct with an unsaturated hydrocarbon polymer; and 
     (b) a polar molecule containing at least one primary or secondary amino group.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part application of U.S. Ser. No. 809,030,filed U.S. Pat. No. 4,652,600 Dec. 16, 1985, which in turn is acontinuation-in-part application of U.S. Ser. No. 778,269, filed Sept.20, 1985, now U.S. Pat. No. 4,587,304.

FIELD OF THE INVENTION

The present invention relates to novel organic compounds and polymerswhich are adducts of sulfomaleic anhydride, its isomers or derivatives,with unsaturated organic molecules wherein the novel products areproduced by contacting sulfomaleic anhydride with an unsaturated organiccompound to form the novel product. In particular, the unsaturatedorganic molecule can be a hydrocarbon polymer ranging in molecularweight from about 500 to about 10,000,000.

The resultant adduct of sulfomaleic anhydride and the unsaturatedhydrocarbon can be further reacted with a polyamine, which willneutralize the sulfonic acid group, as well as covalently bond to thecopolymer by reacting with the anhydride group. The amine salt can beconverted to a metal salt by reaction with metallic bases.

BACKGROUND OF THE INVENTION

Various unsaturated hydrocarbon polymers have been reacted with maleicanhydrides to form a variety of maleic anhydride adducts of unsaturatedhydrocarbon polymers. The reactivity of maleic anhydride with manyunsaturated hydrocarbon polymers is poor and, in some instances, as forexample with EPDM rubber, even employment of extensive heating isineffective. Free radical reactions which graft maleic anhydride ontothe unsaturated hydrocarbon polymer have been utilized as alternativeroutes. Free radical grafting leads to chain scission, crosslinking,grafting onto oils or other paraffinic solvents. The reaction ofsulfomaleic anhydride with the unsaturated hydrocarbon polymer overcomesthese aforementioned deficiencies in that the sulfomaleic anhydride canbe reacted with the unsaturated hydrocarbon polymer at moderatetemperatures in either the bulk or solution state without the employmentof free radical initiators. Utilizing the resultant adduct ofsulfomaleic anhydride with unsaturated hydrocarbons, polar molecules canbe covalently bonded through the anhydride group by reacting theresultant adduct with a a polyamine compound and simultaneouslytherewith, or alternatively thereto, the sulfonic acid group of theresultant adduct can be neutralized with an organic amine, polyamine ormetal counterion. In the case of neutralization of the sulfonic acidgroup the resulting adduct is an ionomer, a polymer which containsphysical links, which is capable of being reprocessed.

SUMMARY OF THE INVENTION

One embodiment of this invention is the production of ion containingpolymers (ionomers), especially sulfonate ionomers, by a non-sulfonationroute. Another embodiment of this invention is the activation of maleicanhydride or its derivatives towards Alder "Ene" reactions orDiels-Alder reactions, such that polymers which have unsaturated siteswill readily form adducts. In particular, polymers such as EPDM rubberswhich do not undergo thermal reaction readily with maleic anhydride willnow react facilely. Still another embodiment is the utilization of theanhydride functionality of the polymer adducts to covalently bond polarmolecules, such as alcohols and amines, to the polymer molecule.Examples of such polar molecules are tetraethylene pentamine,polyethylene amine (PAM), N-amino propyl morpholene, etc.

Examples of sulfomaleic anhydride, its isomers and derivatives which aresuitable for this reaction include, but are not limited to, thefollowing: ##STR1## where R=H, alkyl, aryl, aralkyl, alkaryl, silyl,alkylsilyl, arylsilyl, aminoalkyl, polyether, amino ether, polyamine,etc.

The resultant adduct of sulfomaleic anhydride and the unsaturatedhydrocarbon can be further reacted with: a polyamine which willneutralize the sulfonic acid group, as well as covalently bond to thecopolymer by reacting with the anhydride group; a metal salt or simpleamine which will neutralize the sulfonic acid group to form an ionomer.

The polymers of the instant invention are suitable for use asthermoplastic elastomers, dispersants, viscosity index (VI) improvers,drilling mud viscosifiers and deflocculents, adhesives, stericstabilizers, flow improvers, wax crystal modifiers, crystallinepolyolefin modifiers, polymer blend stabilizers and other applicationsobvious to those skilled in the art.

These products are also useful for combined application, such ascombined dispersant and VI improvers. Such materials are known asmultifunctional VI improvers since they combine dispersant and viscosityimprover characteristics into a single molecule. Multi-functionalviscosity improvers are preferred since they can have betterviscometrics than systems with lower molecular weight dispersants.

EPDM or EP polymers which have been reacted with maleic anhydride andsubsequently modified by reacting the anhydride with polar molecules,such as polyamines, are of interest as multifunctional viscosityimprovers. This is a relatively cumbersome reaction since EPDM andmaleic anhydride are not reactive. Treating the two together in ahydrocarbon oil with radical initiators results in grafting of not onlythe polymer but also the oil. In contrast, the combination ofsulfomaleic anhydride or its derivatives with EPDM is a rapid reactionwhich does not require initiators or extremely high temperature and doesnot involve the hydrocarbon solvent. The reaction also takes placereadily in the absence of solvent upon admixture with the bulk rubber.Thus, an anhydride is present on the polymer molecule and can be reactedwith polar molecules, such as polyamine, to produce a multi-functionalviscosity improver.

GENERAL DESCRIPTION

The present invention relates to polymers which are sulfomaleicanhydride adducts with unsaturated hydrocarbons which are formed byreacting sulfomaleic anhydride with an unsaturated hydrocarbon in eitherthe solution or the bulk state.

Sulfomaleic anhydride, which is represented by the formula: ##STR2## orformed by reacting maleic anhydride with sulfur trioxide. Besidessulfomaleic anhydride one can also employ sulfomaleic acid, sulfofumaricacid, sulfoacrylic anhydride and their various mono- and/or diesters,mono- and/or di-amides or imide derivatives.

The sulfomaleic anhydride is reacted with an unsaturated hydrocarbonpolymer which is selected from the group consisting of EPDM terpolymers,EPR, polyisoprene, polybutadienes, Butyl rubber, styrene-butadiene andstyrene-isoprene "random" and block copolymers, polybutenes, hydrocarbonresins, such as Escorez resins, etc. oligomers or polymers which haveolefin functionality near the end of the chain are of interest. Reactionwith sulfomaleic anhydride and any subsequent reaction with polarmolecules, such as amine alcohols, polyols, polyamines, give a "diblock"with a hydrocarbon tail and a polar head. Such molecules include, butare not limited to, polyisobutene and polybutenes of various molecularweights. Vistanex, and Vistanex-J are examples of such polymers.

The expression "Butyl rubber", as employed in the specifications andclaims, is intended to include copolymers made from a polymerizationreaction mixture having therein from 70 to 99.5% by weight of anisobutylene and about 0.5 to 30% by weight of a conjugated multiolefinhaving from about 4 to 14 carbon atoms, e.g., isoprene. The resultingcopolymer contains 85 to 99.8% by weight of combined isoolefin and 0.2to 15% of combined multiolefin.

Butyl rubber generally has a Staudinger molecular weight as measured byGPC of about 20,000 to about 500,000, preferably about 25,000 to about400,000, especially about 10,000 to about 400,000, and a Wijs Iodine No.of about 0.5 to 50, preferably 1 to 15. The preparation of Butyl rubberis described in U.S. Pat. No. 2,356,128, which is incorporated herein byreference.

For the purposes of this invention the Butyl rubber may haveincorporated therein from about 0.2 to 10% of combined multiolefin;preferably about 0.5 to about 6%, more preferably about 1 to about 4%,e.g., 2%.

Illustrative of such a Butyl rubber is Exxon Butyl 365 (Exxon ChemicalCompany), having a mole percent unsaturation of about 2.0% and a Mooneyviscosity (ML, 1+3. 212° F.) of about 40 to 50.

Low molecular weight Butyl rubbers, i.e., Butyl rubbers having aviscosity average molecular weight of about 5,000 to 85,000, and a molepercent unsaturation of about 1 to about 5%, may be sulfonated toproduce the polymers useful in this invention. Preferably, thesepolymers have a viscosity average molecular weight of about 25,000 toabout 60,000.

The EPDM terpolymers of the instant invention are low unsaturatedpolymers having about 1 to about 10.0 weight percent olefinicunsaturation, more preferably about 2 to about 8, most preferably about3 to 7, defined according to the definition as found in ASTM-1418-64,and is intended to mean terpolymers containing ethylene and propylene inthe backbone and a diene in the side chain. Illustrative methods forproducing these terpolymers are found in U.S. Pat. No. 3,280,082,British Pat. No. 1,030,289 and French Pat. No. 1,380,600, which areincorporated herein by reference. The preferred polymers contain about40 to about 75 weight percent ethylene and about 1 to about 10 weightpercent of a diene monomer, the balance of the polymer being propylene.Preferably, the polymer contains about 45 to about 70 weight percentethylene and about 1 to about 10 weight percent of a diene monomer, thebalance of the polymer being propylene. Preferably, the polymer containsabout 45 to about 70 weight percent ethylene, e.g., 50 weight percent,and about 2.6 to about 8.0 weight percent diene monomer, e.g., 5.0weight percent. The diene monomer is preferably a nonconjugated diene.

Illustrative of these nonconjugated diene monomers which may be used inthe terpolymer (EPDM) are 1,4-hexdadiene, dicylcopentadiene,5-ethylidene-2-norbornene, 5-methylene-2-norbornene,5-propenyl-norbornene and methyl tetrahydroindene.

A typical EPDM is Vistalon 2504 (Exxon Chemical Company), a terpolymerhaving a Mooney viscosity (ML, 1+8, 212° F.) of about 40 and having anethylene content of about 50 weight percent and a5-ethylidene-2-norbornene content of about 5.0 weight percent. The M_(n)as measured by GPC of Vistalon 2504 is about 47,000, the M_(v) asmeasured by GPC is about 145,000, and the M_(w) as measured by GPC isabout 174,000.

Another EPDM terpolymer, Vistalon 2504-20, is derived from Vistalon 2504(Exxon Chemical Company) by a controlled extrusion process wherein theresultant Mooney viscosity at 212° F. is about 20. The M_(n) as measuredby GPC of Vistalon 2504-20 is about 260,000, the M_(v) as measured byGPC is about 90,000, and the Md_(w) measured by GPC is about 125,000.

Nordel 1320 (DuPont) is another terpolymer having a Mooney viscosity at212° F. of about 25 and having a 53 weight percent of ethylene, about3.5 weight percent of 1,4-hexadiene, and about 43.5 weight percent ofpropylene.

The EPDM terpolymers of this invention have a number average molecularweight (M_(n) as measured by GPC of about 10,000 to about 200,000, morepreferably of about 15,000 to about 100,000, most preferably of about20,000 to about 60,000. The Mooney viscosity (ML, 1+8, 212° F.) of theEPDM terpolymer is about 5 to about 670, more preferably about 10 toabout 50, most preferably about 15 to about 40. The M_(v) as measured byGPC of the EPDM terpolymer is preferably below about 350,000 and morepreferably below about 300,000. The M_(w) as measured by GPC of the EPDMterpolymer is preferably below about 500,000 and more preferably belowabout 350,000.

Other suitable olefin polymers include polymers comprising a major molaramount of C₂ to C₅ monoolefins, e.g., ethylene, propylene, butylene,isobutylene pentene-1, octene-1, etc. The polymers may be homopolymers,such as polyisobutylene, as well as copolymers of two or more sucholefins, such as copolymers of ethylene and propylene, butylene andisobutylene, propylene and isobutylene and the like. Preferably thesepolymers will contain some diene so as to provide residual unsaturatedsites.

The olefin polymers will usually have number average molecular weightwithin the range of about 750 and about 200,000, more usually to about20,000. Particularly useful olefin polymers for dispersant additiveshave number average molecular weights (Mn) within the range of about 900to about 2,000, with approximately one terminal bond per polymer chain.Especially useful material in the present invention is polyisobutylene.Polybutene-1 and polypropylene are also preferred hydrocarbonsubstituents for preparing dispersants.

Sulfonated EPDM and EPT rubbers are also of interest as viscosity indeximprovers. The excellent viscometrics of these materials is attributedto the effect of temperature upon the ionic association equilibrium. Thereaction of sulfomaleic anhydride or its derivatives with EPDM can alsoproduce sulfonate (and carboxylate) sites on EPDM's. The resultingproducts and their metal or amine (ammonium) salts are useful as VIimprovers.

The reaction of the sulfomaleic anhydride with the unsaturatedhydrocarbon polymer can occur in solution, in a melt and in polymericprocessing equipment, such as a rubber mill, a Brabender, an extruder ora Banbury mixer.

The adduct of sulfomaleic anhydride with the unsaturated hydrocarbon canbe covalently bonded through its anhydride group with moleculescontaining polar groups. Such polar functionality molecules can be lowmolecular weight compounds, oligomers or polymers. Of particularinterest are molecules containing amine or hydroxyl functionality. Thereaction of the polyamine with the sulfomaleic adduct with unsaturatedhydrocarbon polymer will form amides (imides) and the reaction with apolyols compound will form esters. Polyamines or polyols providepolarity to form molecules with a polar head and a hydrocarbon tail inaddition to the ionic sulfonate group.

The polyamines of the instant invention have about 2 to about 30 carbonatoms, more preferably about 2 to about 20, and most preferably about 4to about 12. Typical examples of suitable polyamines are ethylenediamine, diethylene triamine, triethylene tetramine, tetraethylenepentamine, and N,N-dimethyl ethylene diamine.

The sulfonic acid group of the sulfomaleic anhydride can be neutralizedwith ammonia, primary, secondary or tertiaryy amines, including theaforementioned amino compounds, or metal counterion selected from thegroup consisting of iron, lead, aluminum and Groups IA, IIA, IB and IIBof the Periodic Table of Elements. The neutralization of the sulfonicacid groups of the sulfomaleic anhydride adduct of the unsaturatedhydrocarbon polymer can be accomplished either in solution, in a melt orin polymeric processing equipment, as previously defined.

The oil soluble reaction products of the invention can be incorporatedin a wide variety of oleaginous compositions. They can be used inlubricating oil compositions, such as automotive crankcase lubricatingoils, automatic transmission fluids, etc., in concentrations generallywithin the range of about 0.01 to 20 weight percent, e.g., 0.1 to 10weight percent, preferably 0.3 to 3.0 weight percent, of the totalcomposition. The lubricants to which the products can be added includenot only hydrocarbon oils derived from petroleum but also includesynthetic lubricating oils, such as polyethylene oils, alkyl esters ofdicarboxylic acid, complex esters of dicarboxylic acid, polyglycol andalcohol, alkyl esters of carbonic or phosphoric acids, polysilicones,fluorohydrocarbon oils, mixtures of mineral lubricating oil andsynthetic oils in any proportion, etc.

When the products of this invention are used as multifunctionaladditives having detergency and anti-rust properties in petroleum fuels,such as gasoline, kerosene, diesel fuels, No. 2. fuel oil and othermiddle distillates, a concentration of the additive in the fuel in therange of 0.001 to 0.5 weight percent, based on the weight of the totalcomposition, will usually be employed.

When used as an antifoulant in oil streams in refinery operations toprevent fouling of process equipment, such as heat exchangers, or inturbine oils, about 0.001 to 2 weight percent will generally be used.

The additive may be conveniently dispensed as a concentrate comprising aproportion of the additive, e.g., 20 to 90 parts by weight, dissolved ina proportion of a mineral lubricating oil, e.g., 10 to 80 parts byweight, with or without other additives being present.

In the above compositions or concentrates other conventional additivesmay also be present, including dyes, pour point depressants, antiwearagents, such as tricresyl phosphate or zinc dialkyldithiophosphates of 3to 8 carbon atoms in each alkyl group, antioxidants, such as N-phenylalpha-naphthylamine, tert-octylphenol sulfide, 4,4'-methylenebis-(2,6-di-tert butyl phenol), deemulsifiers, such as polysiloxanes,ethoxylated polymers and the like.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following Examples illustrate the present invention without,however, limiting the same hereto.

EXAMPLE 1 EPDM Rubber With Sulfomaleic Anhydride

A solution of 50 g of dry EPDM rubber (Vistalon 2504) in 1 liter of dryxylene was heated and stirred under nitrogen and 2.67 g (15 mmole) ofsulfomaleic anhydride was added and heating continued for 4 hours.

After cooling the sulfonic acid was neutralized and the anhydridereacted with excess methylamine (21.2 g). The polymer solution becameextremely viscous and began to climb the stirrer, indicating that apolymeric methylammonium sulfonate ionomer had been formed. Methanol (50ml) was added to attenuate the strong intermolecular associations andthe viscosity gradually decreased.

After standing overnight the polymer was precipitated in a high speedmixer with 4,000 ml of isopropyl alcohol-water (70:30), collected on afilter and washed again in the mixer with another portion of IPA-water.A small quantity of Irganox 1010 antioxidant was added and the polymerfiltered and vacuum dried at 50° C.

Microanalysis indicated that the resulting product contained 0.46% S(14.4 mmole/100 g) and 0.265% N (18.9 mmole/100 g).

Treatment of a solution of the modified polymer in 95:5 toluene:methanolwith excess sodium methoxide in methanol to free ionically boundmethylamine and isolation gave a product whose analysis showed 0.40% S(12.5 mmole/100 G) and 0.115% N (8.2 mmole/100 g).

EXAMPLE 2 EPDM Rubber With Chlorosulfonyl Maleic Anhydride

According to the method of Example 1, 2.95 g of chlorosulfonylmaleicanhydride was reacted with 50 g of Vistalon 2504 EPDM rubber, followedby reaction of the sulfonyl chloride and carboxylic anhydride groupswith excess methylamine. The polymer was isolated and cleaned as inExample 1.

Microanalysis indicated the presence of 0.46% S (14.3 mmole/100 g) and0.359% N (25.6 meq/100 g). Some gelation of the polymer product wasobserved.

Treatment of this polymer with sodium methoxide solution and isolationas in Example 1 gave a product whose microanalysis showed 0.39% S (12.2mmole/100 g) and 0.194% N (13.8 mmole/100 g).

EXAMPLE 3 Butyl Rubber With Chlorosulfonyl Maleic Anhydride

According to the method of Example 1, 2.95 g of chlorosulfonyl maleicanhydride was reacted with 50 g of Butyl rubber (Exxon 365 Butylrubber). After treatment with methylamine the isolated polymer contained0.47% S (14.7 mmole/100 g) and 0.468% N (33.4 mmole/100 g). Furtherreaction with sodium methoxide gave a polymer whose elemental analysisshowed a 0.45% S (14.0 mmole/100 g) and 0.215% N (15.3 mmole/100 g).

EXAMPLE 4 EPDM Rubber With 2-Chloroformyl-3-Sulfoacrylic Anhydride

According to the method of Example 1, 50 g of EPDM (Vistalon 2504) and2.95 g of 2-chloroformyl-3-sulfoacrylic anhydride were reacted. Aftertreatment with methylamine the isolated polymer contained 0.40% S (12.5mmole/100 g) and 0.445% N (31.8 mmole/100 g). After treatment withsodium methoxide the isolated polymer gave the following microanalysis:0.52% S (16.3 mmole/100 g) and 0.205% N (14.6 mmole/100 g).

EXAMPLE 5 EPDM Rubber With the Methyl Ester of Chlorosulfonyl MaleicAnhydride

Chlorosulfonyl maleic anhydride was reacted with one molar equivalent ofmethanol in chloroform solution. The chloroform was removed under vacuumand 3.43 g of the resulting product was reacted with 50 g of Vistalon2504 EPDM according to the method of Example 1. After treatment withmethylamine the isolated polymer, according to microanalysis, contained0.38% S (11.9 mmole/100 g) and 0.179% N (12.8 mmole/100 g). Aftertreatment with sodium methoxide the analysis showed 0.36% S (11.2mmole/100 g) and 0.089% N (6.4 mmole/100 g).

EXAMPLE 6 Conjugated Diene Butyl with Sulfomaleic Anhydride

According to the method of Example 1, 2.67 g of sulfomaleic anhydridewas reacted with 50 g of CD Butyl 7614. After treatment with methylamineand isolation the product contained 0.38% S (11.9 mmole/100 g) and0.248% N (17.7 mmole/100 g).

EXAMPLE 7 Bulk Reaction of EPDM With Sulfomaleic Anhydride

Vistalon 2504 EPDM (50 g) was fluxed on a 3" electric mill at 120° C.Sulfomaleic anhydride (1.05 g) was added slowly. After the the additionwas complete the sample was mixed for a new minutes and zinc stearate(2.35 g) was added and mixing continued for a few minutes longer.

That resulting product was a tough, elastic material that resembled acrosslinked rubber. However, the product was soluble in 95:5toluene:methanol, indicating that the product was a thermoplasticelastic "ionomer".

EXAMPLE 8 Aminopropyl Morpholine Derivative of EPDM-SulfomaleicAnhydride Adduct

Sulfomaleic anhydride (2.67 g) was reacted with 50 g of Vistalon 2504EPDM according to the method of Example 1. After 1 hour heating wasdiscontinued, then 7.21 g of aminopropyl morpholine was added at 110° C.The reaction mixture became extremely viscous and was difficult to stir.Methanol addition (50 ml) cut the viscosity appreciably. The mixture wascooled and stirred for 1 hour; then it was precipitated in 4 liters70:30 IPA:water in a high speed mixer and washed twice in the mixer withtwo portions of IPA containing a small quantity of antioxidant. Thedried polymer was analyzed, redissolved, reprecipitated as before, driedand reanalyzed. This procedure was repeated again. Finally, a solutionof the twice-purified polymer was treated with sodium methoxide,precipitated, washed and isolated as before. The results are tabulatedbelow.

    ______________________________________                                        Vistalon 1504 + Sulfomaleic Anhydride                                         Treated with Aminopropylmorpholine                                                                                 Meq N/                                                       Meq S/100 g      100 g                                    Purification % S    Polymer     % N  Polymer                                  ______________________________________                                        Initial Product                                                                            0.38   11.9        0.415                                                                              29.6                                     First Reprecip.                                                                            0.44   13.7        0.329                                                                              23.5                                     Second Reprecip.                                                                           0.36   11.2        0.282                                                                              20.1                                     Sodium Methoxide                                                              Treatment of 0.34               0.128                                         Second Reprecip.                                                                           0.30               0.150                                                      0.32   9.98        0.139                                                                              9.92                                     ______________________________________                                    

EXAMPLE 9 Tetraethylene Pentamine Derivative of EPDM-SulfomaleicAnhydride Adduct

According to the Method of Example 8, tetraethylene pentamine wassubstituted for n-aminopropyl morpholine. Some crosslinking wasapparent. The results are tabulated below.

    ______________________________________                                        Vistalon 2504 EPDM + Sulfomaleic Anhydride                                    Reacted With Tetraethylene Pentamine                                                                                Meq N/                                                       Meq S/100 g      100 g                                   Purification                                                                              % S      Polymer    % N   Polymer                                 ______________________________________                                        Initial Product                                                                            0.477              1.161                                                     0.45                1.170                                                     0.46     14.3       1.166 83.2                                    First Reprecip.                                                                           0.49                0.850                                                     0.52                0.841                                                      0.505   15.7       0.846 60.4                                    Second Reprecip.                                                                          0.43                0.829                                                     0.42                0.838                                                      0.425   13.3       0.834 59.5                                    Sodium Methoxide                                                              Treatment   0.42                0.582                                         Second Reprecip.                                                                          0.47                0.584                                                      0.445   13.9       0.583 41.6                                    ______________________________________                                    

EXAMPLE 10 Aminopropyl Morpholine Derivative of Low Molecular WeightEPDM-Sulfomaleic Anhydride Adduct

Example 8 was repeated using a low molecular weight (8 Mooney) EPDM. Theresults are tabulated below.

    ______________________________________                                                                              Meq N/                                                       Meq S/100 g      100 g                                   Purification                                                                              % S      Polymer    % N   Polymer                                 ______________________________________                                        Initial Product                                                                           0.25     7.80       0.392 28.1                                    First Reprecip.                                                                           0.24     7.48       0.273 19.4                                    Second Reprecip.                                                                          0.22     6.86       0.262 18.7                                    Sodium Methoxide                                                              Treatment   0.25                0.114                                         Second Reprecip.                                                                          0.24                0.114                                                      0.245   7.64       0.114 8.14                                    ______________________________________                                    

EXAMPLE 11 Aminopropyl Morpholine Derivative of EPDM-MethoxysulfonylMaleic Anhydride

The methyl sulfonate ester of maleic anhydride ##STR3## was reacted with50 g of Vistalone 22504 EPDM in 1,000 ml xylene at about 130° C. for 4hours and 5.19 g of N-(3-aminopropyl) morpholine was added. A viscosityincrease was noted, stirring was continued overnight.

The adduct was precipitated in 5 liters of IPA in a high speed mixer,washed twice with 2 liter portions of IPA and dried overnight in vacuumat 50° C.

The product was analyzed, dissolved in 1,500 ml 95:5 toluene:methanoland precipitated in 8 liters 70:30 IPA:H₂ O, washed with IPA, dried andanalyzed. The product was redissolved and reprecipitated once more.

The twice reprecipitated product was treated with sodium methoxideaccording to the method of Example 1. The results are tabulated below.

    ______________________________________                                                                              Meq N/                                                       Meq S/100 g      100 g                                   Purification                                                                              % S      Polymer    % N   Polymer                                 ______________________________________                                        Initial Product                                                                           0.76     23.7       0.818 58.4                                    First Reprecip.                                                                           0.73     22.8       0.688 49.1                                    Second Reprecip.                                                                          0.75     23.4       0.651 46.5                                    Sodium Methoxide                                                              Treatment of                                                                              0.66     20.6       0.605 43.2                                    Second Reprecip.                                                                          0.69     21.5       0.624 44.6                                                         21.1             43.9                                    ______________________________________                                    

EXAMPLE 12 Polyisobutylene with Sulfomaleic Anhydride

About 250 g of polyisobutylene (Mn {90) was dissolved in 200 ml xyleneat room temperature under a nitrogen blanket. To the stirred xylenesolution was gradually added 60 g of sulfomaleic anhydride at about 35°C. The reaction mixture was refluxed for about 8 hours and thenconcentrated by roto-evaporation. The residue was taken up in 2.5 L ofether and washed twice with 500 ml portions of water. The ether solutionwas dried over MgSO₄, filtered and concentrated by roto-evaporation. Thedried sulfomaleated product analyzed for 0.33% sulfur and showed astrong anhydride carbonyl adsorption band at ca. 5.6 microns in theinfrared.

EXAMPLE 13 Tetraethylenepentamine (TEPA) Derivative ofPolyisobutylene-Sulfomaleic Anhydride Adduct

Twenty grams of the adduct obtained in Example 12 were aminated with 1.9g of TEPA by heating a mixture of the reactants at 165° C. for about 4hours. The resulting product featured an infrared spectrum with a strongimide carbonyl absorption band at ca. 5.9 microns, and analyzed for 2.6%nitrogen. The product was diluted with an equal weight of mineral oil(solvent 150N) for bench testing.

EXAMPLE 14 Additive Testing

In Table 1 below the products of this invention were evaluated forvarnish potency in the VIB (Varnish Inhibition Bench) test. Comparativetests with prior art products were also conducted. These tests aredescribed below.

In the VIB test a test sample consisting of 10 g of lubricating oilcontaining the additive being evaluated is used. The test oil is acommercial a lubricating oil obtained from a taxi after 2,000 miles ofdriving with said lubricating oil. Each sample is heat soaked overnightat about 140° C. and thereafter centrifuged to remove the sludge. Thesupernatant fluid of each sample is subjected to heat cycling from about150° C. to room temperature over a period of 3.5 hours at a frequency ofabout 2 cycles per minute. During the heating phase a gas containing amixture of 0.7 volume percent SO₂, 1.4 volume percent NO and the balanceair was bubbled through the test samples and during the cooling phasewater vapor was bubbled through the test samples. At the end of the testperiod, which testing cycle can be repeated as necessary to determinethe inhibiting effect of any additive, the wall surfaces of the testflasks in which the samples were contained are visually evaluated as tovarnish inhibition. The amount of varnish deposited on the walls israted as a numerical value of from 1 to 10, with the higher numberreflecting the greater amount of varnish. It has been found that thistest correlates with the varnish results obtained from ASTM-MS-VC enginetests.

EXAMPLE 15 Evaluation of Candidate Additives in the VIB Test

A series of VIB evaluations were carried out to measure the potency ofseveral of the additives of the present invention as varnish inhibitors.Included in the testing of comparative purposes are two additives, CA-1and CA-2, which are representative of commercially available productsused to control sludge and varnish in engines. CA-1 is a polyisobutenylsuccinimide dispersant made by aminating polyisobutenyl succinicanhydride (Mn=900) with tetraethylene pentamine. CA-2 is amultifunctional viscosity modifier (MFVM) obtained by free radicalgrafting of 2-vinylpyridine onto ethylene-propylene (EP) copolymer. Inevaluating the relative activities of the commercial-type additives andthe additives of the present invention similar treat levels of additivewere employed. These results are illustrated in the table below.

                  TABLE I                                                         ______________________________________                                        Varnish Inhibition Bench (VIB) Test                                           Results on Candidate Additives                                                Additive        % N    VBI Rating                                             ______________________________________                                        Dispersant                                                                    Example 13      1.3    3                                                      CA-1            1.58   7                                                      MFVM                                                                          Example 8       0.42   3                                                      Example 8       0.33   3                                                      Example 10      0.39   3                                                      Example 10      0.26   3                                                      CA-2            0.3    4                                                                             10                                                     ______________________________________                                    

The data clearly indicate that the dispersant and MFVM additives of theinstant invention control varnish more effectively than thecorresponding commercial type of dispersant or MFVM additives.

What is claimed is:
 1. A covalently bonded reaction product of polymer comprising:(a) a sulfomaleic anhydride adduct with an unsaturated hydrocarbon polymer, wherein said unsaturated hydrocarbon polymer is selected from the group consisting of ethylene propylene terpolymers, ethylene diene copolymers, propylene diene copolymers, polyisoprene, Butyl rubber, polybutadiene and styrenebutadiene, and styrene-isoprene random and block copolymers, polypropylenes and polyisobutylenes, and the sulfonic acid groups of the sulfomaleic anhydride adduct with the unsaturated hydrocarbon polymer are neutralized with a metal counterion selected from the group consisting of iron, aluminum, lead and Groups IA, IIA, IB and IIB of the Periodic Table of Elements; and (b) a polar molecule containing at least one primary or secondary amino group.
 2. The polymer adduct of claim 1 wherein the sulfomaleic derivative or isomer is selected from the group including halosulfonyl maleic anhydride, alkoxysulfonyl maleic anhydrides, halocarbonyl-B-sulfoacrylic anhydrides, alkyl or aryl silyl oxysulfonyl maleic anhydrides.
 3. A polymer according to claim 1 wherein said polar molecule is selected from the group consisting of polyamines having about 2 to about 30 carbon atoms.
 4. A polymer according to claim 1 wherein said polar molecule is aminopropyl morpholine.
 5. A polymer according to claim 1 wherein said polar molecule is tetraethylene pentamine.
 6. A polymeric solution comprising a hydrocarbon liquid and about 0.01 to about 90 weight percent of a covalently bonded reaction product of:(a) a sulfomaleic anhydride adduct with an unsaturated hydrocarbon polymer, wherein said unsaturated hydrocarbon polymer is selected from the group consisting of ethylene propylene terpolymers, ethylene diene copolymers, propylene diene copolymers, polyisoprene, Butyl rubber, polybutadiene and styrenebutadiene, and styrene-isoprene random and block copolymers, polypropylenes and polyisobutylenes and the sulfonic acid groups of the sulfomaleic anhydride adduct with the unsaturated hydrocarbon polymer are neutralized with a metal counterion selected from the group consisting of iron, aluminum, lead and Groups IA, IIA, IB and IIB of the Periodic Table of Elements; and (b) a polar molecule containing at least one primary or secondary amino group.
 7. A lubricating oil comprising an oil and about 0.01 to about 20 percent of a covalently bonded reaction product of:(a) a sulfomaleic anhydride adduct with an unsaturated hydrocarbon polymer, wherein said unsaturated hydrocarbon polymer is selected from the group consisting of ethylene propylene terpolymers, ethylene diene copolymers, propylene diene copolymers, polyisoprene, Butyl rubber, polybutadiene and styrenebutadiene, and styrene-isoprene random and block copolymers, polypropylenes and polyisobutylenes and the sulfonic acid groups of the sulfomaleic anhydride adduct with the unsaturated hydrocarbon polymer are neutralized with a metal counterion selected from the group consisting of iron, aluminum, lead and Groups IA, IIA, IB and IIB of the Periodic Table of Elements; and (b) a polar molecule containing at least one primary or secondary amino group. 